So all the items exported to google via the google channel in my store do not contain the item_group_id, and this is causing variants of the same product to show up multiple times and with different prices (since each variant is priced differently in my store).
I noticed that a very small number of my products do have item_group_id, and those are the ones for which inventory is tracked by shopify (others I do not need to track inventory since I make them on demand so I unchecked the “track quantity” box)
Keep in mind that even turning on inventory tracking for an existing product does NOT fix the issue, it works for new products added with quantity tracking turned on, and I definitely do not fancy adding over 700 products to my store again.
Any idea how one could fix this issue?